Trading carbon for food: Global comparison of carbon stocks vs. crop yields on agricultural land
Expanding croplands to meet the needs of a growing population, changing diets, and biofuel production comes at the cost of reduced carbon stocks in natural vegetation and soils. Here, we present a spatially explicit global analysis of tradeoffs between carbon stocks and current crop yields. The difference among regions is striking. For example, for each unit of land cleared, the tropics lose nearly two times as much carbon (∼120 tons·ha-1 vs. ∼63 tons·ha-1) and produce less than one-half the annual crop yield compared with temperate regions (1.71 tons·ha-1·y-1 vs. 3.84 tons·ha-1·y-1). Therefore, newly cleared land in the tropics releases nearly 3 tons of carbon for every 1 ton of annual crop yield compared with a similar area cleared in the temperate zone. By factoring crop yield into the analysis, we specify the tradeoff between carbon stocks and crops for all areas where crops are currently grown and thereby, substantially enhance the spatial resolution relative to previous regional estimates. Particularly in the tropics, emphasis should be placed on increasing yields on existing croplands rather than clearing new lands. Our high-resolution approach can be used to determine the net effect of local land use decisions.
On the Use of Statistical Models to Predict Crop Yield Responses to Climate Change
Predicting the potential effects of climate change on crop yields requires a model of how crops respond to weather. As predictions from different models often disagree, understanding the sources of this divergence is central to building a more robust picture of climate change's likely impacts. A common approach is to use statistical models trained on historical yields and some simplified measurements of weather, such as growing season average temperature and precipitation. Although the general strengths and weaknesses of statistical models are widely understood, there has been little systematic evaluation of their performance relative to other methods. Here we use a perfect model approach to examine the ability of statistical models to predict yield responses to changes in mean temperature and precipitation, as simulated by a process-based crop model. The CERES-Maize model was first used to simulate historical maize yield variability at nearly 200 sites in Sub-Saharan Africa, as well as the impacts of hypothetical future scenarios of 2◦C warming and 20% precipitation reduction. Statistical models of three types (time series, panel, and cross-sectional models) were then trained on the simulated historical variability and used to predict the responses to the future climate changes. The agreement between the process-based and statistical models' predictions was then assessed as a measure of how well statistical models can capture crop responses to warming or precipitation changes. The performance of statistical models differed by climate variable and spatial scale, with time-series statistical models ably reproducing site-specific yield response to precipitation change, but performing less well for temperature responses. In contrast, statistical models that relied on information from multiple sites, namely panel and cross-sectional models, were better at predicting responses to temperature change than precipitation change. The models based on multiple sites were also much less sensitive to the length of historical period used for training. For all three statistical approaches, the performance improved when individual sites were first aggregated to country-level averages. Results suggest that statistical models, as compared to CERES-Maize, represent a useful if imperfect tool for projecting future yield responses, with their usefulness higher at broader spatial scales. It is also at these broader scales that climate projections are most available and reliable, and therefore statistical models are likely to continue to play an important role in anticipating future impacts of climate change.
The BP Oil Spill: Environmental Justice Implications
Join us for a discussion on human rights and environmental justice implications surrounding the BP oil spill from regulatory, litigation and conceptual perspectives.
Introduced and moderated by Dr. Helen Stacy, Co-ordinator, Program on Human Rights in the Center on Democracy, Development and Rule of Law and Senior Fellow, Freeman Spogli Institute.
Panelists:
Meg Caldwell, Director, Environmental and Natural Resources Law & Policy Program; Executive Director, Center for Ocean Solutions, Woods Institute for the Environment. Professor Caldwell's scholarship focuses on the environmental effects of local land use decisions, the use of science in environmental and marine resource policy development and implementation, and developing private and public incentives for natural resource conservation.
Deborah Sivas, Luke W. Cole Professor of Environmental Law and Director, Environmental Law Clinic. Professor Sivas's current research is focused on the interaction of law and science in the arena of climate change and coastal/marine policy and the ability of the public to hold policymakers accountable.
Ursula Heise, Director, Program in Modern Thought & Literature and Professor of English; member of the Executive Committee of the Program in Science, Technology & Society; Affiliated Faculty of the Woods Institute for the Environment. Author of Sense of Place and Sense of Planet: The Environmental Imagination of the Global (Oxford University Press, 2008), After Nature: Species Extinction and Modern Culture, (forthcoming) and The Avantgarde and the Forms of Nature (in progress).
Stanford Law School
Room 280B
2010 Orientation celebrates FSI's research, educational, and policy endeavors
FSI's 2010 Fall Orientation welcomed faculty, staff, researchers, and friends of the institute to the new academic year and highlighted the institute's diverse research collaborations, educational programs, and policy engagement. Presentations on display and in live video offered highlights of the current work of FSI centers and programs on many of the most challenging issues of the day. In his welcoming remarks, FSI Director Coit Blacker emphasized the interdisciplinary, cross-campus nature of FSI's work and thanked the FSI community for their many contributions to new knowledge and new approaches to many of the most pressing issues on today's global agenda.
This year's Orientation attracted the largest turnout to date. On continual display was a slide show capturing research of FSI centers and programs in the field and multi-disciplinary work here at the institute, along with highlights of FSI conferences, lectures, and policy endeavors compiled by FSI's Nora Sweeny.
Among the highlights were the following displays:
- A presentation by the Center for International Security and Cooperation on the center's research, writing, policy influence, and Track II Diplomacy
- A display of the many books published by the Walter Shorenstein Asia-Pacific Research Center showing the range of economic, political, and regional issues addressed by APARC scholars, and a photo slideshow of recent events and publications demonstrating the breadth of faculty work bridging the U.S. and Asia
- A presentation by The Europe Center, newly launched and housed jointly in FSI and the Division of International and Comparative Area Studies, featuring major research areas, visiting scholars, publications, and notable events
- A presentation by Stanford Health Policy capturing its multidisciplinary work in medicine, law, business, economics, engineering, and psychology
- A presentation by the Ford Dorsey
Program in International Policy Studies, a two-year interdisciplinary
Master's program, which captured the IPS practicum, scholarly concentrations, internships, and careers
- A presentation by the Program on Energy and Sustainable Development featuring its work on environmental and policy research employing state of the art methodology to examine such issues as renewable energy, natural gas markets, national oil companies, low-income energy services, and climate change policy
- A presentation by the Program on Food Security and the Environment which addresses hunger, poverty, and environmental degradation. FSE showcased its current research on topics such as solar electrification, food and nutrition security, climate change and conflicts, and evolving U.S. energy policy, as well as its upcoming series on Food Policy, Food Security, and the Environment
- A presentation by the Stanford Program on International and Cross-Cultural Education, which develops multi-disciplinary curriculum materials on international themes reflecting FSI scholarship. Recent educational projects include a three-part series examining U.S.-South Korean relations, Uncovering North Korea, and Inter-Korean Relations; and a collaboration with TeachAIDS, which works to address and overcome the social and cultural challenges related to HIV/AIDS prevention education through materials offered via the internet and CDs in several languages, http://teachaids.org
- A presentation featuring the Stanford Global Gateway, a comprehensive directory of Stanford in the world
- A presentation previewing the vision and mission of the Stanford Center at Peking University, opening Fall 2011
Other highlights included the presentations prepared by Stanford students who worked in the field this past summer. One group worked in China, developing a survey on nutrition and anemia and their effect on learning, with FSI's Scott Rozelle, Director of the Rural Education Action Program. A second group helped Dr. Paul Wise, professor of pediatrics and Stanford Health Policy core faculty member, evaluate prenatal care in the rural highlands of Guatemala.
Global trends: anticipating key developments through 2025
New PESD Working Paper details challenges of designing carbon offsets for the transportation sector
Sectoral crediting mechanisms such as sectoral no-lose targets have been proposed as a way to provide incentives for emission reductions in developing countries as part of an international climate agreement, and scale up carbon trading from the project-level Clean Development Mechanism to the sectoral level.
Countries would generate tradable emission credits (offsets) for reducing emissions in a sector below an agreed crediting baseline. However, large uncertainties in the regulator's predictions of the counterfactual business-as-usual baseline are likely to render sectoral no-lose targets an extremely unattractive mechanism in practice, at least for the transportation case study presented here. Given these uncertainties, the regulator faces a tradeoff between efficiency (setting generous crediting baselines to encourage more countries to opt in) and limiting transfer payments for non-additional offsets (which are generated if the crediting baseline is set above business-as-usual).
The first-best outcome is attainable through setting a generous crediting baseline. However, this comes at the cost of either increased environmental damage (if developed country targets are not adjusted to account for non-additional offsets), or transfers from developed to developing countries that are likely to be too high to be politically feasible (if developed country targets are made more stringent in recognition that many offsets are nonadditional). A more stringent crediting baseline still generates a large proportion of non-additional offsets, but renders sectoral no-lose targets virtually irrelevant as few countries opt in.
Concern over China at U.S.-ASEAN summit
The United States and the ASEAN group of nations have further strengthened political, economic and security ties, after their second full-scale summit in New York.
President Barack Obama said the Association of Southeast Asian Nations, which groups ten countries, had the potential for true world leadership. President Obama also made it clear that he saw Asia as a vital plank of US foreign policy.
DR EMMERSON: In the run-up to the summit, there was a big question. Would the partnership be declared as being strategic in nature? That was a key word in the discussion and what happened was the leaders basically finessed the issue. It's not hard to suspect that they worried that if they declared a strategic partnership with the United States, this would cause alarm in Beijing. Because let's remember in the run-up to this summit, we've had a lot of activity - the split between China and Japan over the disputed islands, one could continue with some evidence of a more muscular Chinese foreign policy, its commitment to its claim to possess basically the entire South China Sea, escalating that to the level of a core interest, presumably equivalent to their interest in recovering Taiwan. I could go on, but in many case, it was understandable that the subtext of the meeting was what will China think? So basically what the summit did was to finesse the issue. They decided to pass on the question of raising the partnership to quote - a strategic level - unquote, to the ASEAN US Eminent Persons Group, presumably expert advisors that would be convened and would make recommendations down the road.
And one of the most remarkable things about the statement was how much ground it covered. I mean, among the topics and issues that the leaders committed themselves to do something about, were 14 as I count them, 14 different subjects. Human rights, educational change, trade and investment, science, technology, climate change, interfaith dialogue, disaster management, illicit trafficking, international terrorism, I could go on. So it is clear to me that one of the tasks that ASEAN and the US will have to face in the coming months, is to try to insert some sense of priority.
LAM: On that issue of priority, the US President, Barack Obama, of course, postponed a couple of visits to Indonesia due to pressing domestic demands. Did he in anyway express American commitment to the ASEAN region?
DR EMMERSON: Yes, this was particularly kind of, I suppose you could say, evident in the fact that the meeting occurred at all, finally it was organized. It lasted two hours. He was apparently quite engaged and engaging during that period of time. And I think there is no question that the United States under his administration is committed to South East Asia as a region, indeed has agreed with the leaders of ASEAN, that ASEAN should play a central role in the process of building regional cooperation in East Asia.
LAM: And, of course, one of the topics that came up as well was the South China Sea, that entire region, given the competing maritime and territorial claims vis-à-vis the Spratley and Paracel Island groups. Do you think China is watching the US relationship with ASEAN, this growing relationship - do you think Beijing might be watching it with unease?
DR EMMERSON: Yes, absolutely. I am confident that they are watching it with considerable unease and I note that the statement that the leaders made, made no reference whatsoever to the South China Sea, presumably because of sensitivity with regard to Beijing's possible reaction. The topic was implicitly mentioned, but not explicitly.
LAM: And what about within ASEAN, the grouping itself? The UN Secretary-General, Ban Ki-moon, on the weekend said that the ASEAN nations' credibility might suffer if they did not take a tougher line with Burma and this is in view of the upcoming elections in November. This is presumably directed at specifically China and India, but it could also be referenced to ASEAN could it not, because Burma is a member of ASEAN. Do you see that changing anytime soon with ASEAN, that ASEAN countries, leading members like Indonesia, Malaysia, Singapore, that they might take a stronger stand with the military junta in Rangoon?
DR EMMERSON: The election in Myanmar, if I can call it an election, since it will be highly compromised and manipulated will take place, at least is scheduled to take place November 7th. Indonesia does not take over the chairmanship of ASEAN until the 1st January. So the question is, since Indonesia is a democratic country, arguably, the most democratic of any country in South East Asia, will it use its opportunity to try to put pressure on Burma in the year 2011? My own view is that ASEAN will probably not fulfill Ban Ki-moon's hope, will not exercise significant pressure on the junta. Instead, we could get the opposite situation in which so long as there is not major violence associated with the election, it will essentially be received by ASEAN as a kind of minimally-acceptable basis for assuring the Burmese junta that ASEAN still treats them as a full member. In other words, it's quite possible that the junta may get away with what I take to be a kind of facade effort to legitimate their rule.
